I didn't see the yearbook when I went out, but I met the police.

It is the duty of every citizen to cooperate with the police in law enforcement. When the police find suspicious circumstances, it is within the scope of normal law enforcement to take you back to the office for questioning. As for taking the mobile phone away for half an hour, it must be handled by the technical department. If there is no evidence against you, I will let you go. Now that it's okay, forget it.